# US 12,192,502 B2 · Temporal identifier constraints for SEI messages > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,192,502 B2 - Document ID: US12192502B2 - Status: Granted - Kind: B2 - Application number: 17/701,368 - Filed: 2022-03-22 - Published: 2022-07-07 - Granted: 2025-01-07 - Earliest claimed: 2019-09-24 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Ye-Kui Wang - Web page: https://patentgrep.com/patent/US12192502B2 ## CPC - H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) - H04N 19/102: characterised by the element, parameter or selection affected or controlled by the adaptive coding - H04N 19/105: Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction - H04N 19/132: Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking - H04N 19/172: the region being a picture, frame or field - H04N 19/174: the region being a slice, e.g. a line of blocks or a group of blocks - H04N 19/188: {the unit being a video data packet, e.g. a network abstraction layer [NAL] unit} - H04N 21/44004: {involving video buffer management, e.g. video decoder buffer or video display buffer} - H04N 19/30: using hierarchical techniques, e.g. scalability (H04N19/63 takes precedence) - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A video coding mechanism is disclosed. The mechanism includes encoding a coded picture in one or more video coding layer (VCL) network abstraction layer (NAL) units in a bitstream. A non-VCL NAL unit is encoded into the bitstream such that a temporal identifier (TemporalId) for the non-VCL NAL unit is constrained to be equal to a TemporalId of an access unit (AU) containing the non-VCL NAL unit when a NAL unit type (nal_unit_type) of the non-VCL NAL indicates a supplemental enhancement information (SEI) message. A set of bitstream conformance tests is performed on the bitstream based on the SEI message. The bitstream is stored for communication toward a decoder. ## Claims ### Claim 1 A method implemented by a decoder, the method comprising: receiving a bitstream comprising a coded picture in one or more video coding layer (VCL) network abstraction layer (NAL) units and a non-VCL NAL unit, wherein a temporal identifier (TemporalId) for the non-VCL NAL unit is constrained to be equal to a TemporalId of an access unit (AU) containing the non-VCL NAL unit when a NAL unit type (nal_unit_type) of the non-VCL NAL is equal to a prefix supplemental enhancement information (SEI) NAL unit type (PREFIX_SEI_NUT) or a suffix SEI NAL unit type (SUFFIX_SEI_NUT), wherein the non-VCL NAL unit includes a scalable nesting SEI message with a payload type set to one hundred thirty-three, wherein the scalable nesting SEI message contains one or more scalable-nested SEI messages, wherein the scalable nesting SEI message includes an output layer set (OLS) flag equal to one when the scalable-nested SEI messages apply to an OLS and equal to zero when the scalable-nested SEI messages apply to a layer, and wherein the scalable nesting SEI message includes a scalable nesting number of SEIs minus one (num_seis_minus1) plus one that specifies a number of the scalable-nested SEI messages with a value constrained to a range of 0 to 63, inclusive; deriving the TemporalId for the non-VCL NAL unit based on a NAL unit header temporal identifier plus one (nuh_temporal_id_plus1) syntax element in the non-VCL NAL unit; and decoding the coded picture from the one or more VCL NAL units to produce a decoded picture. ### Claim 2 (depends on 1) The method of claim 1, wherein the nal_unit_type of the non-VCL NAL is equal to the PREFIX_SEI_NUT. ### Claim 3 (depends on 1) The method of claim 1, wherein the nal_unit_type of the non-VCL NAL is equal to the SUFFIX_SEI_NUT. ### Claim 4 (depends on 1) The method of claim 1, wherein the coded picture is decoded from the one or more VCL NAL units based on a SEI message in the non-VCL NAL unit. ### Claim 5 (depends on 1) The method of claim 1, further comprising deriving the TemporalId for the non-VCL NAL unit as follows: TemporalId = nuh_temporal ⁢ _id ⁢ _plus1 - 1. ### Claim 6 (depends on 5) The method of claim 5, wherein a value of nuh_temporal_id_plus1 is not equal to zero. ### Claim 7 (depends on 1) The method of claim 1, wherein a TemporalId of the one or more VCL NAL units is constrained to be the same for all VCL NAL units in a same AU. ### Claim 8 (depends on 1) The method of claim 1, wherein the scalable nesting SEI message includes a number of OLSs minus1 (num_olss_minus1) plus 1 that specifies a number of OLSs to which the scalable-nested SEI messages apply. ### Claim 9 A method implemented by an encoder, the method comprising: encoding a coded picture in one or more video coding layer (VCL) network abstraction layer (NAL) units in a bitstream; encoding into the bitstream a non-VCL NAL unit such that a NAL unit header temporal identifier plus one (nuh_temporal_id_plus1) for the non-VCL NAL unit is constrained to be equal to a nuh_temporal_id_plus1 of an access unit (AU) containing the non-VCL NAL unit when a NAL unit type (nal_unit_type) of the non-VCL NAL is a supplemental enhancement information (SEI) message, and wherein the non-VCL NAL unit includes a scalable nesting SEI message with a payload type set to one hundred thirty-three, wherein the scalable nesting SEI message contains one or more scalable-nested SEI messages, wherein the scalable nesting SEI message includes an output layer set (OLS) flag equal to one when the scalable-nested SEI messages apply to an OLS and equal to zero when the scalable-nested SEI messages apply to a layer, and wherein the scalable nesting SEI message includes a scalable nesting number of SEIs minus one (num_seis_minus1) plus one that specifies a number of the scalable-nested SEI messages with a value constrained to a range of 0 to 63, inclusive; performing a set of bitstream conformance tests on the bitstream based on the SEI message. ### Claim 10 (depends on 9) The method of claim 9, wherein the nal_unit_type of the non-VCL NAL is equal to a prefix SEI NAL unit type (PREFIX_SEI_NUT). ### Claim 11 (depends on 9) The method of claim 9, wherein the nal_unit_type of the non-VCL NAL is equal to a suffix SEI NAL unit type (SUFFIX_SEI_NUT). ### Claim 12 (depends on 9) The method of claim 9, wherein a value of nuh_temporal_id_plus1 is not equal to zero. ### Claim 13 (depends on 9) The method of claim 9, wherein a nuh_temporal_id_plus1 of the one or more VCL NAL units is constrained to be the same for all VCL NAL units in a same AU. ### Claim 14 A video decoding device comprising: a receiver configured to receive a bitstream comprising a coded picture in one or more video coding layer (VCL) network abstraction layer (NAL) units and a non-VCL NAL unit, wherein a temporal identifier (TemporalId) for the non-VCL NAL unit is constrained to be equal to a TemporalId of an access unit (AU) containing the non-VCL NAL unit when a NAL unit type (nal_unit_type) of the non-VCL NAL is equal to a prefix supplemental enhancement information (SEI) NAL unit type (PREFIX_SEI_NUT) or a suffix SEI NAL unit type (SUFFIX_SEI_NUT), and wherein the non-VCL NAL unit includes a scalable nesting SEI message with a payload type set to one hundred thirty-three, wherein the scalable nesting SEI message contains one or more scalable-nested SEI messages, wherein the scalable nesting SEI message includes an output layer set (OLS) flag equal to one when the scalable-nested SEI messages apply to an OLS and equal to zero when the scalable-nested SEI messages apply to a layer, and wherein the scalable nesting SEI message includes a scalable nesting number of SEIs minus one (num_seis_minus1) plus one that specifies a number of the scalable-nested SEI messages with a value constrained to a range of 0 to 63, inclusive; and one or more processors coupled to the receiver and configured to: derive the TemporalId for the non-VCL NAL unit based on a NAL unit header temporal identifier plus one (nuh_temporal_id_plus1) syntax element in the non-VCL NAL unit; and decode the coded picture from the one or more VCL NAL units to produce a decoded picture. ### Claim 15 (depends on 14) The video decoding device of claim 14, wherein the nal_unit_type of the non-VCL NAL is equal to the PREFIX_SEI_NUT. ### Claim 16 (depends on 15) The video decoding device of claim 15, wherein the nal_unit_type of the non-VCL NAL is equal to the SUFFIX_SEI_NUT. ### Claim 17 (depends on 16) The video decoding device of claim 16, wherein the coded picture is decoded from the one or more VCL NAL units based on a SEI message in the non-VCL NAL unit. ### Claim 18 (depends on 17) The video decoding device of claim 17, further comprising deriving the TemporalId for the non-VCL NAL unit as follows: TemporalId = nuh_temporal ⁢ _id ⁢ _plus1 - 1. ### Claim 19 (depends on 18) The video decoding device of claim 18, wherein a value of nuh_temporal_id_plus1 is not equal to zero. ### Claim 20 (depends on 14) The video decoding device of claim 14, wherein a TemporalId of the one or more VCL NAL units is constrained to be the same for all VCL NAL units in a same AU.